Rugby Union is a popular team sport that is renowned for its high intensity, full contact playing style. It is a sport that requires a variety of physical characteristics including high degrees of strength expression, power and aerobic ability.
Physiologically, strength may either be isometric or isotonic. Isometric strength relates to muscular contraction against resistance, in which the length of the muscle, once contracted, remains the same. Applying a resistance at a fixed angle, such that there is no movement of the joint, can develop this type of strength. In contrast, isotonic strength relates to muscular contraction in which the muscle remains under relatively constant tension while its length changes. Thus, the muscle has a concentric phase whereby the muscle contracts and shortens, followed by an eccentric phase whereby the muscle lengthens. Raising or lowering a weight can develop this type of strength.
In order to become stronger and obtain muscular hypertrophy, whereby existing muscle fibres are enlarged, it is necessary to overload muscles by making them work beyond a level at which they are accustomed. During weight training, initial gains are primarily due to improvements in inter-muscular coordination (2-4 weeks) and then from adaptations in neural pathways (6-8 weeks). This results in an increase in the number of muscle fibres being used during the exercise and improved efficiency in the way in which they are activated. After approximately 10 weeks muscular hypertrophy becomes apparent and the greater size of the muscle fibres allows for more force to be applied during a single contraction.
Muscle fibres are classified as either Fast Twitch or Slow Twitch, depending on the speed at which they contract. Only if the load is great enough will the faster fibres be employed. Thus, in order to develop these fibres and bring about maximum gains in strength, training with heavy loads is required.
The set scrum is one of the key elements of a game of rugby and requires significant player strength. A scrum consists of eight players from either side competing against each other for possession of the ball following a minor infringement or stoppage. It is one of the few situations where players exert a sustained physical force on their opponents. Scrums form an integral part of the battle for physical and psychological supremacy over the opposition so success in this area is of great interest to coaches and players.
Three players make up the front row of the scrum (or ‘pack’), and hence are the ones in contact with the opposition. The hooker is positioned in the centre of the front row with a prop (loose-head and tight-head) on either side. These players traditionally show high levels of strength, particularly in the neck and back, and are therefore well equipped to exert and withstand the large forces experienced under scrum conditions. The second row of the scrum reinforces the front row and consists of two players. The back row consists of three players, the number 8 with a flanker on either side. The back row locks the formation together to maintain the scrum's integrity.
Each team's pack forms separately approximately 1 m apart, facing towards and slightly offset from the opposing pack. The first stage of the scrum is the ‘crouch and hold’ whereby the players in both packs bend their knees and adopt a crouched position prior to engagement with the opposition. FIG. 1A illustrates the ‘crouch and hold’ position for two opposing teams. For simplicity, only one player from each pack is shown and, in this case, the loose-head prop is shown on the left with the opposing tight-head prop shown on the right.
On engagement, the packs lean towards each other and each of the front row players is required to tuck their head under the chest of their opponent. The ‘engage’ position is shown in FIG. 1B, for the players described above. This position results in the cervical spine, i.e. the neck, of each front row player being in a state of flexion (i.e. where the spine is bent such that the player's chin is forced towards his chest). At this stage it is impossible for two opposing players to both straighten their necks in order to adopt the desired spine-in-line position. During the engagement phase, the horizontal force (FZ) exerted by each pack, is most significant, however, this force decreases rapidly after engagement. It is considered that the engagement force is a function of player mass and speed of engagement and, therefore, it can be maximised through conventional bulk training.
The next stage of a scrum involves the adoption of the correct body position for attacking. This stage is crucial for successful scrummaging and is illustrated in FIG. 1C. Thus, the attacking player manages to extend his cervical spine by forcing his head upwards into the chest of the opponent, whilst at the same time using his chest to put pressure on the back of the opponent's head. Consequently, the attacking player is able to adopt the spine-in-line body position that is required for exerting the optimal force on his opponent. As a result of the above, the defending player is forced to adopt a poor body position with extreme flexion of the cervical spine and poor thoracic spinal alignment. Thus, the defending player is severely disadvantaged for exerting any force on his opponent. Cervical torque (TC), i.e. the force applied to rotate the head, is the most significant force applied during adoption of the correct body position.
Once the correct body position has been adopted, the attacking player is able to exert more force than his opponent. This stage of the scrum is called the sustained push phase and is illustrated in FIG. 1D. Thus, the attacking player uses his lower back strength and isotonic knee extension to lift and drive his opponent backwards, past the mark of the scrum. Horizontal force (FZ), vertical force (FY) and cervical torque (TC) are all significant during the sustained push phase.
In view of the above, the most important stage for successful scrummaging is the adoption of the correct body position immediately after engagement. In order for a player to be able to adopt the desired spine-in-line position, isotonic cervical extension strength (ICES) is required. Thus, whichever player has the greatest ICES is likely to be able to adopt this position first and immediately be at an advantage over his opposition, since the player with the correct body position can more easily exert the forces FZ and FY that are required for pushing his opponent backwards.
The benefits of strength training in rugby are well documented and it is common practice for players of all positions and at all levels to undergo such training as part of their preparation to meet the demands of the sport. However, there is a lack of specific conditioning equipment for the players in the front row of the scrum. Much attention is paid to well-established strength training exercises such as squats and dead lifts, but usually little time is spent strengthening the more crucial muscle groups in the neck and back, especially those responsible for extension of the neck (i.e. moving the head backwards and lifting the chin off the chest). Players must be naturally strong in these areas, or must undergo ‘live’ scrummaging exercises over many years, to be proficient in this aspect of the game.
In addition to the above, it is commonly believed that the better prepared a player is, physically, to cope with the demands of the game, the less likely it is for him or her to suffer an injury. In rugby generally, and in particular during scrums, there have been a number of catastrophic spinal injuries, in the large part due to ‘hyperflexion’ (i.e. bending beyond the normal range) of the cervical spine. It is conceivable that by strengthening the muscles of the neck, players would have added protection against this mechanism of injury, and would therefore be at a reduced risk of serious injury or paralysis.
Conventional scrummaging machines are widely used by schools and rugby clubs across the globe. The most commonly used machine is an outdoor roller-type machine intended for use by the entire pack. However, there are a number of variations including sleds and fixed-frame machines whereby pads are pushed back and forth along runners held under tension by springs. Although these machines can offer modest strength gains, their primary goal is teambuilding and the coaching of individual technique.
There are also a small number of individual scrum machines, notably those manufactured by Rhino, Predator and MyoQuip. Both the Rhino and Predator machines attempt to provide a measurement of pushing strength or ‘scrummaging strength’ using a pneumatic system. The MyoQuip ‘Scrum Truck’ on the other hand, is a weight-based system that aims to develop horizontal pushing power while maintaining the body position adopted in a scrum or maul.
In addition, there are a number of more complex systems such as the Scrum Master ‘International’ and a system used by the French rugby club of Toulouse that is described in WO2005/044402. These systems include advanced computer control and are capable of being programmed to provide feedback to the user. In particular, the Toulouse machine includes pads arranged to receive a substantially horizontal force from the shoulders of a user and a substantially vertical force from the back of the head of a user. The pads are connected to a support frame through resistive joints such that a measurement of the force exerted on the pads can be obtained. U.S. Pat. No. 5,324,247 describes an apparatus and method for multi-axial spinal testing and rehabilitation. U.S. Pat. No. 3,216,724 describes a football practice apparatus.
It is an aim of the present invention to provide an improved muscle conditioning apparatus that will enable front row forwards in particular, to enhance their scrummaging performance.